Method and apparatus for radiosignaling.



R. A. WEAGANT.

METHOD AND APPARATUS FOR RADIOSIGNALING.

APPLICATION FILED JAN. 6, 1916.

a/ Aw 11v VENTOR liqy fl Malaya/w BYWa/M A TTORNE Y ROY ALEXANDER WEAGANT, F ROSELLE,

LESS TELEGRAPH COMPANY OF AMERI NEW JERSEY.

Specification of Letters Patent.

NEW JERSEY, ASSIGNOR '1'0 MARCONLWIRE- CA, 01? NEW YORK..N. Y., A CORPORATIONOF METHOD AND APPARATUS FOR RADIOSIGNALIN G.

Patented Jul 23, 1918.

Application filed .Tanuary G, 1916. Serial N 0. 70,571.

To all whom it may concern:

Be it known that I, ROY A. WEAGANT, a

. citizen of the United States, residing in the town of Roselle, county of Union, State of New Jersey, have made certain new and useful Improvements in Methods of and Apparatus for Radiosignaling, of which the following is a specification.

This invention relates to improvements in the art of and apparatus for radio signaling and employs a receiving antenna constructed to exclude interfering electromagnetic waves of a frequency considerably higher than the frequency of the incoming waves to which the receiving apparatus is adapted and adjusted to respond as in the process of receiving signals due to the transmission from a distant station, and to do this in a more effective manner than has heretofore been found possible. The object of the improvement is to avoid interfering electromagnetic waves of different frequency than, for the time being, are used for signaling.

It is commonly noted that while an aerial 0r antenna system, by means of the ordinary tuning methods, can be so adjusted as to respond to a maximum extent to electromagnetic waves having a definite period yet it is also commonly observed that such an aerial system will oscillate at its own period when excited by electromagnetic waves havinga widely different period; this is exceptionally true when such different magnetic waves are quite strong or emanate from a nearby, powerful transmitter, or are the re sult of static disturbances. The purpose of this invention is to make the antenna system less responsive to disturbances of this sort or character.

The usual arrangement of elevated wire is or may be employed; but included, preferablyat' regular intervals, there are fixed inductances which ma be'of substantially equal value and in the orm of closely wound coils. This antenna is associated with a receiving circuit having well known, adjustable means for tuning and it results from the construction and arrangement described that, when receiving electromagnetic waves. of predetermined frequency waves of higher frequency or shorter wave lengths are effectively excluded.

While experimenting with the large receiving aerial constructed by the Marconi Company at New Brunswick, New Jersey, which aerial has a natural period of a proximately 7,000 meters, I found great dithculty ineliminating interference due to stations having a wave length quite short in comparison say, from 600 to 3,000 meters,-

and that the usual methods of tuning would not effectively eliminate these interfering Waves. I conceived that the reason for this was the fact that the inductance and capacity of the antenna were distributed in a uniform manner and that, therefore, the aerial itself was capable of vibrating at periods other than its fundamental. It appeared to me, also, that the remedy for this condition was in an aerial constructed with a number of inductance coils located at separated points throughout the length of the antenna and I therefore constructed such an aerial at the laboratory of the Marconi Company in Union county, New Jersey, and-I found that its effect in this respect was very great. When listening to signals transmitted, for instance, from N auen, Gen many, with the ordinary type of antenna the operation of testing transmitters in course of manufacture in the factory building .immediately adjacent to this antenna, but not connected to it, made such reception entirely impossible and that furthermore, a number of other stations, such as New York navy yard, Sea Gate, New York, and others, caused a sufiicient disturbance to greatly interfere with reception of signals from Nauen, the wave length of which station is understood to be, approximately, 12,000 meters, while that of the interfering stations named ranges from 600 to 2,000 meters.

When, however, my novel type of aerial is employed, other conditions being identical, I have found that it is possible to receive these signals from N auen .without interference from the other stations named. I also find'that this antenna is most effective when receiving continuous oscillations and its receiving efficiency, as compared to an ordinary antenna, is greater when receiving continuous oscillations than it is when receiving damped oscillations.

The accompanying drawings illustrate the invention. Figure 1 shows my improvedre ceiving antenna Fig. 2 is amodification; Fig. 3-shows a cooperating .transmittlng c11'-.

cuit at a distant point or station.

In each figure-of the drawing there is an a detector. 14, of any suitable kind, telephone receiver 15 or other indicating instrument and a bridging condenser 16. In Fig. 2 theantenna a, has a horizontal sectlon 20,

of considerable extent, suitably supported on towers or other supports 21. Inductance coils areconnected at intervals in the antenna a, the same as in Fig. 1. In

Fig. 3 there is shown a motor generator ar- .quency rangement the generator is a high frealternatingcurrent generator 31 in.

a circuit 32 which includes a Morsetransmitting key 33; there is the primary coil of "an inductorium, 34, having a secondary coil 35 with magnetic wire core 36; coil 35 is in the closed oscillating circuit with a condenser 37, a quenched gap 38, and the primary coil of a transformer 39 having an adjustable secondary coil {l0 in the antenna (1.

During regular normal operation ofthe transmitter 'oscillations of predetermined frequency are apparent in the antenna a of the receiving stations, Figs. 1 and 2. While receiving the transmitted signals, at such receiving station, any interfering signals or impulses from whatever source, or any source, either natural or artificial, of greater or higher frequency than, at the time, is being used for the described signaling are noninterfering and are not apparent in the receiving apparatus. This is due to the pres ence. in the receiving apparatus of the described series of inductances, or concentrated inductance, 111 the receiving antenna 1mparting a fundamental characteristic to the antenna which appears to block out oscillations of higher frequency. V

The operation of my improved apparatus may be in part explained as follows, al-

though it is not to be understood as being a definite explanation of its entire action:

An ordinary antenna has inductance, re.- sistance andcapacity constants more or less uniformly distributed throughout its length.

It results fromthis that the antenna may be caused to vibrate, as'described above, at

its own periodicity, either by repeated ap-' plications of minute. impulses at the frequency of the antenna, as by received oscillations from the sending station, or by a species of electrical. shock, such as might be t y 0. r. .me -dir c io a i11 pulses or oscillatory impulses of relatively great strength, but of a periodicity different from that of the antenna. Such impulses, as I have stated above, may proceed from a neighboring transmitting station, or from static disturbances. i

In my improved device, by distributing the constants ofthe antenna throughout its length, in a uniform manner, as by-connecting concentrated inductances at intervals (not' necessarily regular) along the antenna in any desirable manner, the antenna is so constitutedthat it will not respond to shock,

but will nevertheless be entirely responsive- .to repeated applications of energy.

A species of electrical inertia, so to speak, has thus been imparted to the system, which resists the wide oscillations produced by shock, but does not prevent the setting up of oscil- P lations by the repeated application of energy at the periodicity of the antenna. This is probably due to the fact that the subdivision of the antenna into severalgparts,

bythe inclusion of the concentrated inductances, permits the electromotive force of the shock oscillation to be propagated a limited distance only along the antenna before meeting with a reflection point, or point of abrupt change of constants, such reflecting points producing increased efi'ects athigher frequencies. While I oscillations is employed, and that it may be used either for radio'telegraphy or radio telephony.

While I .have conclusively proven the beneficial and novel results to be obtained with my construction in connection with have. described my method and apparatus in connection with a receiving sta-' -tion for radio telegraphy, that being a con nection in which it displays marked usefulinterference due to disturbances of higher I frequency or shorter wave lengththan that to which my new aerial is tunedfI have not had equal opportunityto test it against I interference or from disturbances of greater 'wave length. I have, therefore, largely confined my description to the exclusion of such higher frequencies. While I cannot state it with equal certainty, I believe it to be the fact, from such tests as I have been able to make, that it is ofgreat benefit in preventing interference from longer Waves thanthose to which the aerial is turned, and I do not desire to limit my claims-in this respect, other forth in them. 7

I I have actually used fixed inductances of equal value and at regular intervals, and I than by the construction "set ha e found this structure effective, but I do not limit myself in this regard, except as specified in my claims:

What I claim is:

1. In apparatus of the kind described, an open antenna circuit system having means for producing a plurality of reflection points distributed substantially throughout its length. I

2. The method of radio signaling which consists in setting up oscillations in an open antenna by repeated applications of impulses at a desired frequency, and setting up at points throughout the antenna reactions opposed to oscillations of undesired frequencies.

3. In apparatus of the kind described, an antenna consisting substantially throughout its len -th of a plurality of sections having distri uted capacity and inductance only and connected to each other by inductance coils through which the current passing from one to the other is forced to flow.

4. In apparatus of the kind described, a receiving open antenna having adjustable inductance therein and having at points outside said adjustable inductance and distributed throughout the length of said antenna, a plurality of concentrated inductances, in combination with means, at a distant station, for generating and transmitting oscillations of cooperating characteristics.

5. The method of radio signaling which consists in setting up oscillations in an open antenna by repeated applications of i111- pulses at a desired frequency, and setting up at points distributed substantially throughout the length of the antenna reactions opposed to oscillations of undesired frequencies.

ROY ALEXANDER WVEAGAN T. 

